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1998 Jeep Grand Cherokee ZJ - Grand Slam

Posted in Features on April 7, 2014
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The iconic open-top Jeep is in many ways one of the best platforms for building a hard- core off-road rig. The lack of sheetmetal (read no permanent bendable roof), fold-down (and easily replaceable) windshield frame, and tons of aftermarket support means CJs or Wranglers are usually the first Jeeps to be built with big tires and a heavy-duty drivetrain. But sometimes that just does not make sense. One such case where a CJ or Wrangler build would just not fit the bill was when Jason Woods of Alamogordo, New Mexico, wanted to build an enclosed (read sealed from the elements) family wheeler. You see, Jason and his family were planning to attend the All For Fun Jeep event in Lake County, Colorado, this past summer. With wet and muddy trails, 12,000-foot elevations, and fickle weather that may result in freezing rain or snow, he knew his current rig (an open top YJ on 42s with no heater) wasn’t gonna keep the family happy. Jason hoped to find a TJ or LJ for the base of his family wheeler project. Jason knew he wanted a V-8, climate controls, and big tires, but look as he may nothing TJ-based came up without being well outside his price range. That is until he widened his gaze a bit and came across someone selling a Grand Cherokee project that had stalled. The end result is the clean and well-built Jeep Grand Cherokee ZJ you see before you here.

Keep in mind that the pictures you see here were shot at All For Fun in early August 2013. That’s about three months after Jason bought the Grand Cherokee as an uncompleted project in April of 2013. That’s a quick build by anyone’s standards, especially when you consider how much work Jason did himself to the uncompleted project. Having said that, the Clayton Off Road 7-inch long-arm suspension was mostly in place and the 1-ton axles were already under the Jeep when Jason got it. Jason had plans for big tires so he started cutting sheetmetal and stretched the front control arms about 4 inches to move the tires away from the firewall. While doing this the front suspension was also converted from a radius arm style to a true three-link with a track bar. The third upper link twists at the axle end via 2.63-inch forged Ballistic Joint and a Johnny Joint on the frame side. Out back the Clayton four-link was also stretched about 1.5 inches for maximum wheelbase and rear door to front of rear tire clearance. Limiting straps are used both front and rear to control the droop and keep the Clayton-sourced springs in place on the Jeep during flex. Shocks on all four corners are 11-inch-travel Bilstein 5100s.

Having the huge front tires pushed so far forward means lots of sheetmetal has to be removed or modified, and we’ll talk more about that in a bit, but the trimming kinda speaks for its self. The front inner fenderwells were massively modified for clearance and stock steel was replaced with 14-gauge bits to help retain the Unitbody’s structural strength. Material was also added to the pseudo framerails in the front section of the Unitbody toward the front bumper. The Jeep’s stock lead-acid battery was replaced by a sealed Optima Yellow Top, mounted in a Blue Torch Fab battery box. Both were then placed at an angle under the hood to clear the modified front inner wheelwell. The home-built front bumper, formed of 3⁄16-inch plate, holds a Warn XD9000 winch while adding rigidity to the Unitbody framerails at the front of the Jeep. Below and mounted to the bumper is a Skyjacker Rock Lock sway bar designed for a TJ to help control sway on-road and allow it in the dirt.

The Jeep Grand Cherokee ZJ’s factory power steering box was leaking like a stuck pig so Jason replaced it with a rebuilt Wagoneer box that was tapped by West Texas Off Road for hydraulic ram assist. Jason then added in an 8-inch stroke ram from PSC to further help direct the soon-to-be-spinning 40s. To help slow the big four-door Jason robbed the hydroboost and master cylinder from a ’03 Duramax. With the addition of the steering and brake upgrades the stock power steering pump was not up to snuff. To resolve this, a rebuilt type two Saginaw power steering pump with a remote reservoir tap from a ’90s XJ was sourced. The pressure valve was massaged for maximum output and then Jason tracked down a junkyard-fresh power steering reservoir from a ’95 BMW 740IL to handle all that fluid. The German part fits the bill with its steel construction, and Jason also adds that, “It has several return ports and a replaceable internal filter as well as a screen on the large filler cap to keep out dirt.” Cool!

In the rear of the Jeep the fenders were basically comp-cut for massive rear tire clearance. Stock structural sheetmetal from behind the rear wheelwells was replaced with 16-guage steel boxed panels to retian rigidity and to allow Jason to keep the Jeep Grand Cherokee ZJ’s rear hatch in place. The rear bumper is made from 3⁄16-inch rectangular tubing that was notched and formed to match the contour of the rear of the body and maintain the rear hatch’s seal. The rear bumper also adds rigidity to the Unitbody’s overall structure much like the front bumper.

PhotosView Slideshow

Once Jason got the Grand Cherokee in his hands he went through everything “that holds fluids, oils, or grease.” That meant replacing and rebuilding most of the cooling system, adding new hoses, a water pump, a timing chain and cover, and a radiator. Jason also had to toss a set of polyurethane motor and tranny mounts at the 5.2L V-8. The factory NP249 T-case was dropped and replaced with a NP231J from a ’97 TJ. The NP231 also received a slip-yoke eliminator as well as a 2-Lo conversion to the internal shifter plate. Custom driveshafts were built front and rear and use 1310-size U-joints and double-cardan joints on the T-case end of things. Downhill from the T-case lives a kingpin Dana 60 front axle from a ’79 Ford. This axle features a custom “home brew” mini truss for the axle end of the third upper link. Out back a home-shaved GM Corporate 14-bolt (that now has 13-bolts in the cover) turns the tires and is held in place with another home-built truss and Clayton lower control arm brackets. The rear axle was modified with disc brakes using brackets from Great Lakes Off Road and GM front rotors and calipers. Gears both front and rear are 5.13s and spin both axleshafts come what may thanks to a pair of venerable Detroit Lockers.

Body and Interior
In addition to the extensive modifications made to the Grand’s Unitbody, front and rear fenders Jason also raised the position of stock gas tank. This was accomplished by basically cutting the floor over the fuel tank out of the back of the ZJ’s body. The remaining sheetmetal was then folded down, gusseted with more steel, and welded in place. This allowed the tank to be moved up about 9 inches between the pseudo-framerails of the Jeep. Below the tank a new skidplate and fuel tank support was built out of 1⁄8-inch plate steel. Then the fuel filler was rerouted and a new “floor” was constructed in the back of the Jeep to make sure fuel and fuel vapors have a hard time getting inside the passenger compartment of the Grand. The aforementioned front and rear fenders were carefully trimmed as high as possible and feature cleanly radiused cuts. The rear cut starts at the bottom of the front of the rear wheelwell, leaving just enough metal to weld up the seam and extends all the way back to the brake light. The rear brake light housings were also cut down to size and a new sealed bottom attached. The interior of the ZJ remains basically stock with upgrades in the form of Dickies seat covers from “Wally World,” a Cobra CB radio, an old head unit with an input jack and a USB port, and most importantly for family peace and comfort, both the factory heater and A/C.

PhotosView Slideshow

Good, Bad, and What It’s For
We love the low stance and huge tires on this Grand Cherokee. It looks great and works well for a nearly completed build (As if any Jeep is ever complete!). Jason hit the mark when he set out to build a family friendly off-road Jeep that is capable and comfortable. We really wish the Jeep had a rollcage that is as stout and well-built as the rest of the rig. The good news on that front is Jason has a Rock Hard 4x4 rollcage for the ZJ and is just waiting for some extra time to install it. Jason also needs to build some stout rocker guards, and given the other things he’s done to the Grand we are sure they will be stout and well thought out once together. Since we shot the feature on the Grand Jason has made a few changes like adding a set of 40x13.50R17 Nitto Mud Grapplers mounted on the same Soft 8 wheels that were modified with DIY weld on bead locks from Total Metal Innovations. Jason also plans on replacing the Jeeps’ coil springs and shocks with a set of ORI struts he has also sitting on a shelf waiting for time to install them.

Hard Facts
Vehicle: ’98 Jeep Grand Cherokee ZJ
Engine: 5.2L V-8
Transmission: 44RE four-speed auto
Transfer Case: NP231J
Suspension: Three-link with track bar (front); four-link with triangulated uppers (rear)
Axles: Dana 60 (front); Corporate 14-bolt (rear)
Wheels: 17x8 Soft 8 steel
Tires: 40x13.5R17 Goodyear MT/R
Built For: Taking the family…anywhere

Why I Wrote This Feature
I was at All For Fun with Discount Tire’s RESQ1 project when I saw this ZJ in the parking lot. It was different enough catch my eye and the large tires and beefy parts made me think of ZJs that I have built in my mind for years. I left my business card on the windshield and went back to playing with RESQ1, hoping the owner would call me up. Jason quickly did and then was nice enough to wait around for a while, while I finished up my RESQ1 chores. We then rolled up one of the trails to an old abandoned mine so I could shoot photos late in the afternoon. I dig the Jeep because it is, in my opinion, what more people should build. Added beef where necessary, but without the fluff and frills that make things gaudy.

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